1 files changed, 324 insertions, 0 deletions
diff --git a/net/ipv6/ila/ila_lwt.c b/net/ipv6/ila/ila_lwt.c
new file mode 100644
index 000000000..3d56a2fb6
--- /dev/null
+++ b/net/ipv6/ila/ila_lwt.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/errno.h>
+#include <linux/ip.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/socket.h>
+#include <linux/types.h>
+#include <net/checksum.h>
+#include <net/dst_cache.h>
+#include <net/ip.h>
+#include <net/ip6_fib.h>
+#include <net/ip6_route.h>
+#include <net/lwtunnel.h>
+#include <net/protocol.h>
+#include <uapi/linux/ila.h>
+#include "ila.h"
+
+struct ila_lwt {
+	struct ila_params p;
+	struct dst_cache dst_cache;
+	u32 connected : 1;
+	u32 lwt_output : 1;
+};
+
+static inline struct ila_lwt *ila_lwt_lwtunnel(
+	struct lwtunnel_state *lwt)
+{
+	return (struct ila_lwt *)lwt->data;
+}
+
+static inline struct ila_params *ila_params_lwtunnel(
+	struct lwtunnel_state *lwt)
+{
+	return &ila_lwt_lwtunnel(lwt)->p;
+}
+
+static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	struct dst_entry *orig_dst = skb_dst(skb);
+	struct rt6_info *rt = (struct rt6_info *)orig_dst;
+	struct ila_lwt *ilwt = ila_lwt_lwtunnel(orig_dst->lwtstate);
+	struct dst_entry *dst;
+	int err = -EINVAL;
+
+	if (skb->protocol != htons(ETH_P_IPV6))
+		goto drop;
+
+	if (ilwt->lwt_output)
+		ila_update_ipv6_locator(skb,
+					ila_params_lwtunnel(orig_dst->lwtstate),
+					true);
+
+	if (rt->rt6i_flags & (RTF_GATEWAY | RTF_CACHE)) {
+		/* Already have a next hop address in route, no need for
+		 * dest cache route.
+		 */
+		return orig_dst->lwtstate->orig_output(net, sk, skb);
+	}
+
+	dst = dst_cache_get(&ilwt->dst_cache);
+	if (unlikely(!dst)) {
+		struct ipv6hdr *ip6h = ipv6_hdr(skb);
+		struct flowi6 fl6;
+
+		/* Lookup a route for the new destination. Take into
+		 * account that the base route may already have a gateway.
+		 */
+
+		memset(&fl6, 0, sizeof(fl6));
+		fl6.flowi6_oif = orig_dst->dev->ifindex;
+		fl6.flowi6_iif = LOOPBACK_IFINDEX;
+		fl6.daddr = *rt6_nexthop((struct rt6_info *)orig_dst,
+					 &ip6h->daddr);
+
+		dst = ip6_route_output(net, NULL, &fl6);
+		if (dst->error) {
+			err = -EHOSTUNREACH;
+			dst_release(dst);
+			goto drop;
+		}
+
+		dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
+		if (IS_ERR(dst)) {
+			err = PTR_ERR(dst);
+			goto drop;
+		}
+
+		if (ilwt->connected)
+			dst_cache_set_ip6(&ilwt->dst_cache, dst, &fl6.saddr);
+	}
+
+	skb_dst_set(skb, dst);
+	return dst_output(net, sk, skb);
+
+drop:
+	kfree_skb(skb);
+	return err;
+}
+
+static int ila_input(struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct ila_lwt *ilwt = ila_lwt_lwtunnel(dst->lwtstate);
+
+	if (skb->protocol != htons(ETH_P_IPV6))
+		goto drop;
+
+	if (!ilwt->lwt_output)
+		ila_update_ipv6_locator(skb,
+					ila_params_lwtunnel(dst->lwtstate),
+					false);
+
+	return dst->lwtstate->orig_input(skb);
+
+drop:
+	kfree_skb(skb);
+	return -EINVAL;
+}
+
+static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
+	[ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
+	[ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
+	[ILA_ATTR_IDENT_TYPE] = { .type = NLA_U8, },
+	[ILA_ATTR_HOOK_TYPE] = { .type = NLA_U8, },
+};
+
+static int ila_build_state(struct nlattr *nla,
+			   unsigned int family, const void *cfg,
+			   struct lwtunnel_state **ts,
+			   struct netlink_ext_ack *extack)
+{
+	struct ila_lwt *ilwt;
+	struct ila_params *p;
+	struct nlattr *tb[ILA_ATTR_MAX + 1];
+	struct lwtunnel_state *newts;
+	const struct fib6_config *cfg6 = cfg;
+	struct ila_addr *iaddr;
+	u8 ident_type = ILA_ATYPE_USE_FORMAT;
+	u8 hook_type = ILA_HOOK_ROUTE_OUTPUT;
+	u8 csum_mode = ILA_CSUM_NO_ACTION;
+	bool lwt_output = true;
+	u8 eff_ident_type;
+	int ret;
+
+	if (family != AF_INET6)
+		return -EINVAL;
+
+	ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla, ila_nl_policy, extack);
+	if (ret < 0)
+		return ret;
+
+	if (!tb[ILA_ATTR_LOCATOR])
+		return -EINVAL;
+
+	iaddr = (struct ila_addr *)&cfg6->fc_dst;
+
+	if (tb[ILA_ATTR_IDENT_TYPE])
+		ident_type = nla_get_u8(tb[ILA_ATTR_IDENT_TYPE]);
+
+	if (ident_type == ILA_ATYPE_USE_FORMAT) {
+		/* Infer identifier type from type field in formatted
+		 * identifier.
+		 */
+
+		if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) {
+			/* Need to have full locator and at least type field
+			 * included in destination
+			 */
+			return -EINVAL;
+		}
+
+		eff_ident_type = iaddr->ident.type;
+	} else {
+		eff_ident_type = ident_type;
+	}
+
+	switch (eff_ident_type) {
+	case ILA_ATYPE_IID:
+		/* Don't allow ILA for IID type */
+		return -EINVAL;
+	case ILA_ATYPE_LUID:
+		break;
+	case ILA_ATYPE_VIRT_V4:
+	case ILA_ATYPE_VIRT_UNI_V6:
+	case ILA_ATYPE_VIRT_MULTI_V6:
+	case ILA_ATYPE_NONLOCAL_ADDR:
+		/* These ILA formats are not supported yet. */
+	default:
+		return -EINVAL;
+	}
+
+	if (tb[ILA_ATTR_HOOK_TYPE])
+		hook_type = nla_get_u8(tb[ILA_ATTR_HOOK_TYPE]);
+
+	switch (hook_type) {
+	case ILA_HOOK_ROUTE_OUTPUT:
+		lwt_output = true;
+		break;
+	case ILA_HOOK_ROUTE_INPUT:
+		lwt_output = false;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (tb[ILA_ATTR_CSUM_MODE])
+		csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]);
+
+	if (csum_mode == ILA_CSUM_NEUTRAL_MAP &&
+	    ila_csum_neutral_set(iaddr->ident)) {
+		/* Don't allow translation if checksum neutral bit is
+		 * configured and it's set in the SIR address.
+		 */
+		return -EINVAL;
+	}
+
+	newts = lwtunnel_state_alloc(sizeof(*ilwt));
+	if (!newts)
+		return -ENOMEM;
+
+	ilwt = ila_lwt_lwtunnel(newts);
+	ret = dst_cache_init(&ilwt->dst_cache, GFP_ATOMIC);
+	if (ret) {
+		kfree(newts);
+		return ret;
+	}
+
+	ilwt->lwt_output = !!lwt_output;
+
+	p = ila_params_lwtunnel(newts);
+
+	p->csum_mode = csum_mode;
+	p->ident_type = ident_type;
+	p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]);
+
+	/* Precompute checksum difference for translation since we
+	 * know both the old locator and the new one.
+	 */
+	p->locator_match = iaddr->loc;
+
+	ila_init_saved_csum(p);
+
+	newts->type = LWTUNNEL_ENCAP_ILA;
+	newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT |
+			LWTUNNEL_STATE_INPUT_REDIRECT;
+
+	if (cfg6->fc_dst_len == 8 * sizeof(struct in6_addr))
+		ilwt->connected = 1;
+
+	*ts = newts;
+
+	return 0;
+}
+
+static void ila_destroy_state(struct lwtunnel_state *lwt)
+{
+	dst_cache_destroy(&ila_lwt_lwtunnel(lwt)->dst_cache);
+}
+
+static int ila_fill_encap_info(struct sk_buff *skb,
+			       struct lwtunnel_state *lwtstate)
+{
+	struct ila_params *p = ila_params_lwtunnel(lwtstate);
+	struct ila_lwt *ilwt = ila_lwt_lwtunnel(lwtstate);
+
+	if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64,
+			      ILA_ATTR_PAD))
+		goto nla_put_failure;
+
+	if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode))
+		goto nla_put_failure;
+
+	if (nla_put_u8(skb, ILA_ATTR_IDENT_TYPE, (__force u8)p->ident_type))
+		goto nla_put_failure;
+
+	if (nla_put_u8(skb, ILA_ATTR_HOOK_TYPE,
+		       ilwt->lwt_output ? ILA_HOOK_ROUTE_OUTPUT :
+					  ILA_HOOK_ROUTE_INPUT))
+		goto nla_put_failure;
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static int ila_encap_nlsize(struct lwtunnel_state *lwtstate)
+{
+	return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */
+	       nla_total_size(sizeof(u8)) +        /* ILA_ATTR_CSUM_MODE */
+	       nla_total_size(sizeof(u8)) +        /* ILA_ATTR_IDENT_TYPE */
+	       nla_total_size(sizeof(u8)) +        /* ILA_ATTR_HOOK_TYPE */
+	       0;
+}
+
+static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
+{
+	struct ila_params *a_p = ila_params_lwtunnel(a);
+	struct ila_params *b_p = ila_params_lwtunnel(b);
+
+	return (a_p->locator.v64 != b_p->locator.v64);
+}
+
+static const struct lwtunnel_encap_ops ila_encap_ops = {
+	.build_state = ila_build_state,
+	.destroy_state = ila_destroy_state,
+	.output = ila_output,
+	.input = ila_input,
+	.fill_encap = ila_fill_encap_info,
+	.get_encap_size = ila_encap_nlsize,
+	.cmp_encap = ila_encap_cmp,
+	.owner = THIS_MODULE,
+};
+
+int ila_lwt_init(void)
+{
+	return lwtunnel_encap_add_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);
+}
+
+void ila_lwt_fini(void)
+{
+	lwtunnel_encap_del_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);
+}